Lamp



Sept. 8, 1931. w. E. WUELKER LAMP Original Filed Sept. 14, 1925 2 Sheets-Sheet 1 f Mad/law Sept. 8, 1931. w. E. wuELKl-:R

LAMP

original Filed sept. 14, 1925 2 sheets-sheet 2 Patented Sept. 8, 1931 UNITED STATES WILLIAM E. WU'ELKER, 0F SAN' FRANCISCO, CALIFORNIA Original application filed September 14, 1925, Serial No. 56,179. Divided and this application filed August 16, 1926. Serial No. 129,585.

This invention relates to lamps of the kind employed for spotpfiood lights for window display Work, in theatre work, for use in lphotographic studios, for use in clinical or dental laboratories, for factory or store illu- "mination, or for other like or similar uses.

This application is a division of my -copending application Serial No. 56,179, filed September 14, 1925.

The objects of the present invention are:

l. To provide a lamp which will more properly diffuse the light;

2. To provide a lamp structure which permits of a novel form of ventilation;

3. To provide a lamp structure which may be detachably connected either with glass or colored gelatin diffusion plates;

4. To provide a lamp having a novel form of light refiecting surface operative to give a desired region of bright intensity in the center of the light 'without bringing the light to a focus; and

5. To provide a novel method of lforming the lamp having the 'above described char- 26 acteristics.

Other objects and advantages of the present invention will be apparent from the description of a preferred form of the lamp embodying the invention and the process of 30 producing the same. Reference is accordingly made to the accompanying drawings,

in which a preferred form of lamp embodying the invention is illustrated.

In the drawings:

Figure l is an elevation mainly in vertical section of a lamp embodying the present invention.

Figure 2 is an elevation of the inner face of a rim constituting a feature of the invention.

Figure 3 is an enlarged perspective View of a detachable diffusion plate means for alternate use of either glass or colored gelatin plates.

Figure 4 is a view of a modified form of socket supporting member illustrating the socket supporting member partly in side elevation and partly in central section.`

Figure 5 is a View of a second modified 60 form of socket supporting member partly in side elevation and partly in central section and illustrating the socket in dotted lines.

Figure 6 is a similar side elevational and central sectional view of a third modified form of socket supporting member for use for border and foot lights.

Figure 7 is a top plan view of the socket supporting member shown in Figure 6.

F1gure 8 is a similar side elevational and central sectional view of a further modified form of socket supporting member adapted for employment in connection with an electrical outlet box.

Figure 9 is a top plan view of the socket supporting member shown in Figure 8. 65

Flgure 10 is a similar side elevational Aand central sectional view of a further modified form of socket supporting member embodied in this invention for employment for exterior use.

Referring to the drawings, the lamp comprises a casing 2 forming a reflecting surface 3 for the lamp, which refiecting surface is of a novel form and particularly adapted for the`proper diffusion and dis- 75 tribution of light. The specific character of this surface, aside from its novel configuration, will be hereinafter described in connection with a description of the process producing it.

The refiecting surface 3 is in the form of two refiecting surfaces 4 and 5, each being so formed that they are approximately between a parabola and an ellipse. The surface 5 is smaller than the surface 4 and is at the base of the total refiecting surface. The two surfaces 4 and 5 have approximately a coincidental focal point and at substantially this focal point is supported a filament 6 of a light bulb 7. Above the part of the casing 2 providing such refiecting surface, said casing connects with a fitting for supporting the lamp and bulb 7 and providing for the proper ventilation in order to eliminate overheating of the bulb 7, the casing 2 connects with a socket supporting member 8 4which may be of any one of the forms hereinafter set forth or any other desired or preferred form of member adapted 100 to support a socket and connect the sameto the casing 2.

At the lower end of the lamp, as viewed in Figure 1, the casing member 2 is provided with means for detachably connecting different light diffusion plates therewith, for which purpose the end of such casing member 2 is flanged outwardly as at 21,` then again downwardly vas at 22 to provide an annular'shoulder against 'which a diffusion plate 23 may be seated. Said diffusion plate 23 is engaged by a rim 24 having a plurality of catches 25 thereon which snap over the flange 22, thus retaining the rim, 24 and thereby the plate 23 in place. In place of the glass diffusion plate 23, the lamp may be closed by gelatin colored plates 26, as illustrated in Figure 3, for which purpose a retainer 27 is also employed, as shown in Figure 3, to hold such plate 26 in place, said member 27 being provided with a plurality of cross wires 28 for supporting the colored plates.

With the lamp thus described, the light from the element 6 of the bulb 7 is generally focused at the proper focus point of both the different reflecting surfaces 4 and 5 of the lamp so that the light is sent out with a zone of increased intensity at its center surrounded by a Zone of somewhat weakened intensity without, however, the light having to be brought to a focus. Moreover, the light sent out is softened and properly diffused and distributed by the joint action of the form of the reflecting surface 3, to be later described, and the diffusion plates 23.

and 26 covering the lamp.

The apertures 13a in the casing member 8a permit the outlet of air from a ventilating space around the base of the bulb 7 of the lamp, permitting circulation of such air through apertures 14a providing a proper ventilation of the lamp and thus avoiding overheating.

The socket supporting member 8, illustrated in Figure 1, comprises a lower casing member 8a and an upper casing member 9a. The lower casing member 8a has a flange 10a formed at its lower end, which fits over the upper end of the upper reflecting surface 5 and is secured thereto by means of set screws 11a. The upper casing 9aL is crimped to the lower casing member 8a, as illustrated at 12a. The vents or perforations 13a are formed at a bent or flared por- 'tion of the lower casing member 8El and the vents or perforations 14a are formed in the upper casing member 9a, so as to permit air circulation for the free ventilation of the lamp mounted within the socket 16a. The cap 17 a is secured above the perforations 14a so as to prevent diffusion of light upward through the said perforations 14a. A ring 18a is secured to the cap 17 a and to the upper inwardly extending portion of the casing arm 21a pivotally secured to the upper casing 9El at a pin 22 which passes through the casing 9a and is maintained in position b means of a nut 23a screw-threaded thereto. A thumb screw 24 is employed for securing the socket supporting member 15t to the supporting arm 21a in any desired adjusted position. The supporting arm 21a has a right angle section 25l which is secured to a mounting bracket 26a at a bolt 27a so that the same may be pivoted or rotated to the desired position.

The supporting bracket 26 has a plurality of pcrforations 28EL formed therein through which set screws, bolts, or other fastening devices, may be extended.

The modified form of socket supporting device 15 shown in Figure 4 is of the ball socket type and comprises a lower casing 8 tapered slightly upwardly and serving as a housing. Any suitable connecting means may be used, the casing 8 being illustrated as flanged outward at 9 and being provided with set screws 10. The upper end of the casing member 8 forms a bead 11 and is secured at the bead 11 to a guide member 12 which serves as a support for steadying the bulb 7. A second or upper casing member 13 is crimped at its lower end and secured to the casing 8 at its lower end. Just below the bead 11 the casing 8 is provided with a series of circumferentially spaced apertures 14 and the guide member 12 isprovided with a series of circumferentially spaced apertures 16. The casing member 13 is belled outward at its lower end to provide a space for the passage of air from the aperture 16 up through the casing 13. The casing 13 is provided at its upper end with a series of circumferentially spaced apertures 17. Said casing 13 supports a bulb socket 18 depending downwardly, as viewed in Figure 4, which socket is connected by a universal joint 19 to a plug 20 by which the electrical connection may be made with the lamp. A set-screw 21 is provided for fixing the joint 19 in any desired adjusted position.

The socket supporting device 15b illustrated in Figure 5 is for the purpose of a drop light, and comprises a casing 8b having a securing flange 10b at its lower end which tion, are adapted to fit, which shade supporting clamps 17b are secured to a lower end of a socket 18b in any desired or preferred manner. The upper end of the casing 8b being opened as at 19, no perforations similar to the perforations 13 are provided, as free circulation is permitted vthrou h the opening 19b to carry away the heat ormed by the globe 7 within the lamp.

The socket supporting member 15, illustrated in Figures 6 and 7, comprises a casing 8 having a ring flange 10 adapted to be secured by set screws 11 to the upper end of the upper reflecting member 5 of the lamp. The upper end of the casing 8 is perforated, as at 13, to pro erly vent the interior of the lamp. The casmg 8 has aninwardly extending ring section 14 which has a plurality of arcuate slots 16 formed therein adapted to fit over the heads of studs 17 so as to secure the casing 8 in position, the heads of the studs 17 fitting through the circular portions 18 of the slots 16. This socket supporting member 15 is well adapted for use in supporting the lamp in connection with border and footlight sockets or outlets.

Thesocket supporting member or attachment 15, illustrated in Figure 8, comprises a casing 8 having a lower end flange 10 adapted to be secured by means of setJ screws 11 to the upper end of the member'forming the upper reflecting surface 5. The casing 8 is perforated, as at 13, for permitting circulation of air. The casing 8 is belled outwardly at 14 and then extended trans-` versely inward at 16 to provide an inner ring section 17 within which varcuateI slots 18 are formed, which arcuate slots 18 have circular sections 19 adapted to fit over the heads of studs 20 for securing the socket supporting member 15 in position. This socket supporting member 15 is well adapted for use in connection with lan outlet box or like purposes.

The socket supporting member 15, illustrated in Figure 10, comprises a casing member 8 having a circular flange 10 at its lower end which is adapted to be engaged with and secured to the upper end of the member forming the upper reflecting surface 5 of the lamp by means of set screws 11. The casing 8 is belled outwardly at its central portion 12 to a ring reinforcing section 13 below which ring reinforcing section 13 a plurality of perforations 14 are member 15 is well adapted for use in connection with outside fixtures.

The valuable. feature in connection with the present lamp is the character of the reflectmg surfaces 4 and 5. In order to obtain pro er surfaces, the reflector is preferably ma e in the following manner, that is, the casing member 2 is spun into its 'desired form from soft aluminum' metal in any usual'or preferred manner. Said member 2 is then. dip ed in and out of a hot concentrated solution of lye in order to cleanse the surface. As the next step in the process, the casing member 2 is dipped into and out of an eating solution preferably of 50% sulfuric acid and 50% nitric acid and therefrom removed and dipped into hot water. The time of treatment for the drying material is preferably about 25 seconds, or until a complete whitening of the reflecting surface is observed. The casing member 2, after being removed from the ,hot water, is then cleaned with sawdust and polished to as high a degree as obtainable. As a final step, the reflecting surface is then washed with a volatile oil, such as gasoline, and then finished by the use of a wire brush wheel.

The resultant effect is that there is provided a highly polished, slightly irregular surface which effects a uniform distribution and diffusion of light from the reflecting surface and'materially softens and improves the character of light sent from the lamp.

While the methods of forming the improved lamp as herein described are well adapted for accomplishing the objects and advantages of this invention, it is to be understood that various modifications in the method of producing the same may be made without departing from the spirit of the invention, and that the invention includes all such modifications and changes as may come within the scope of the appended claims.

Iclaim:

1. In a lamp of the character described, athree-part casing, one part providing a double reflecting surface having a common focal point, the lower end of such part providing an annular flange, a diffusion plate seated against said flange, a rim detachably connected with said member for holding said diffusion plate in place, a second casing part providing the chamber for housing the bulb stem, the last casing member providing a support for the bulb socket and said casings connected together, and means for venti- Ilating the bulb when in said socket through such last two specified casing members.

2. In a lamp of the kind described, .the '.i

cent the saine and having a reflecting surface i operating to reflect and di'use the light received from the first-named reecting surface, said surfaces having substantially coincidental focal points, means for supporting an electric light bulb with its lament substantially at said focal points, a translucent diffusion plate at the outer end of the secondnamed section, said casing having ventilating openings therethrough. Signed at San Francisco, Cal., this 7th day of August, 1926.

WILLIAM E. WUELKER. 

